What are the treatment options for psoriasis?

Psoriasis Treatment

For mild psoriasis (<5% body surface area), start with topical corticosteroids combined with vitamin D analogs as first-line therapy; for moderate-to-severe disease (≥5% BSA), advance to phototherapy (narrowband UVB or PUVA), followed by traditional systemic agents (methotrexate, cyclosporine, acitretin), and reserve biologic agents (IL-17, IL-23, or TNF inhibitors) for severe or refractory cases. 1, 2, 3

Disease Severity Classification

Psoriasis severity determines treatment selection:

• Mild disease: <5% BSA, typically managed with topical therapy alone 1, 3
• Moderate-to-severe disease: ≥5% BSA, or involvement of vulnerable areas (face, genitals, hands, feet, scalp, intertriginous areas), or significant quality of life impact regardless of BSA 1, 2
• Symptomatic psoriasis (pain, bleeding, itching) warrants systemic or phototherapy even with limited BSA involvement 1, 2, 4

Treatment Algorithm by Disease Severity

Mild Psoriasis: Topical Therapies

First-line topical options include:

• Topical corticosteroids: Classified into 7 potency categories; use ultra-high potency (Class I) for thick plaques on trunk/extremities, and low-potency for sensitive areas (face, intertriginous regions) to avoid skin atrophy 1, 4
• Vitamin D analogs: Calcipotriene or calcitriol, maximum 100g per week to avoid hypercalcemia 1, 4
• Combination products: Calcipotriene/betamethasone dipropionate enhances efficacy, reduces irritation, and improves compliance compared to monotherapy 2, 3, 4
• Coal tar preparations: Effective for mild-to-moderate disease with Level I-II evidence 2

For scalp psoriasis specifically: Use calcipotriene foam or calcipotriene plus betamethasone dipropionate gel for 4-12 weeks; consider excimer laser for resistant cases 3, 4

Moderate-to-Severe Psoriasis: Phototherapy

Second-line treatment includes:

• Narrowband UVB phototherapy: First-line phototherapy option 1, 2, 3
• PUVA (psoralen plus UVA): Alternative phototherapy, particularly effective for palmoplantar pustulosis when combined with acitretin 1
• 308-nm excimer laser: For localized resistant areas 4

Apply vitamin D analogs after phototherapy sessions to avoid inactivation 4

Moderate-to-Severe Psoriasis: Traditional Systemic Agents

Third-line treatment options:

• Methotrexate: FDA-approved since 1972, most commonly prescribed traditional systemic agent worldwide; requires regular monitoring of complete blood count, liver function tests, and serum creatinine 1, 3
• Cyclosporine: Highly effective but limited to 1 year in the US (2 years in UK) due to risk of glomerulosclerosis; requires monitoring of blood pressure, renal function, and lipid profile 1, 3
• Acitretin: Consider as first-line for erythrodermic/generalized pustular psoriasis; effective for palmoplantar pustulosis, especially when combined with oral PUVA 1

All traditional systemic agents are absolutely contraindicated in pregnancy 3

Moderate-to-Severe Psoriasis: Biologic Agents

Fourth-line treatment for severe or refractory disease:

• IL-17 inhibitors: Secukinumab, ixekizumab, brodalumab 1, 5
• IL-23 inhibitors: Guselkumab, tildrakizumab, risankizumab 1, 5
• IL-12/23 inhibitor: Ustekinumab 1, 5
• TNF inhibitors: Adalimumab (80 mg initial dose, then 40 mg every other week starting one week after initial dose), etanercept, infliximab 1, 6

For plaque psoriasis, adalimumab is FDA-approved for adults with moderate-to-severe chronic plaque psoriasis who are candidates for systemic therapy or phototherapy, when other systemic therapies are medically less appropriate 6

Psoriatic Arthritis Management

Treatment escalation based on joint involvement:

• Mild joint symptoms: NSAIDs as first-line 1, 2, 3
• Moderate-to-severe joint involvement: DMARDs (methotrexate, sulfasalazine, leflunomide) 1, 2, 3
• Inadequate response to ≥1 DMARD: TNF inhibitors (adalimumab, etanercept, infliximab) 1, 2, 3
• Severe enthesitis: TNF inhibitor after failure of therapies for mild and moderate disease 2

Adalimumab is FDA-approved for reducing signs and symptoms, inhibiting structural damage progression, and improving physical function in adults with active psoriatic arthritis 6

Combination Therapy Strategies

Enhance efficacy by combining treatments:

• Adding ultra-high potency topical corticosteroid to etanercept for 12 weeks improves outcomes in moderate-to-severe psoriasis (Level I evidence) 2
• Adding calcipotriene/betamethasone to adalimumab for 16 weeks accelerates plaque clearance 2
• Adding topical calcipotriene to methotrexate enhances efficacy in moderate-to-severe psoriasis (Level I evidence) 2
• All topical corticosteroids can be combined with any biologic for moderate-to-severe disease 2

Rotational therapy (switching between treatment modalities every 1-2 years) may minimize cumulative toxicity 2, 4

Critical Pitfalls to Avoid

• Never use systemic corticosteroids as monotherapy for psoriasis—they cause severe disease flare during or after taper 1, 2, 3, 4
• Long-term potent topical corticosteroids cause skin atrophy, striae, and telangiectasia 2, 3, 4
• Limit moderately potent topical corticosteroids to ≤100g per month with regular clinical review and no unsupervised repeat prescriptions 2, 4
• Drugs that worsen psoriasis: Alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine 2, 4
• Commercial sunbeds are rarely effective and may cause premature skin aging and increased skin fragility 3

Monitoring Requirements

For methotrexate: Regular monitoring of complete blood count, liver function tests, and serum creatinine; consider pharmacogenetic testing to predict efficacy and safety 1, 3

For cyclosporine: Regular monitoring of blood pressure, renal function, and lipid profile 3